The present invention relates to a vehicle control device mounted in a vehicle brake hydraulic pressure control system such as an anti-lock brake system (ABS), a traction control system (TRC) or an electronic stability control system (ESC).
This type of vehicle control device is shown in FIG. 6. As shown, it includes a hydraulic unit (HU) 1, a motor M mounted on one side of the hydraulic unit, and an electronic control unit (ECU) mounted on the other side of the hydraulic unit. The hydraulic unit 1 includes a reservoir 3, a pump 4, control valves 5 for pressure increase, and control valves 6 for pressure reduction, which are all mounted in an aluminum housing 10. The housing 10 is formed with master cylinder ports 7 which communicate with wheel cylinder ports 8 through passages 9a in which the control valves 5 for pressure increase are provided. The wheel cylinder ports 8 also communicate with the reservoir 3 through passages 9b in which the control valves 6 for pressure reduction are provided. The reservoir 3 also communicates with the wheel cylinder ports 8 through passages 9c in which the pump 4 and the control valves 5 for pressure increase are provided.
The electronic control unit 2 includes a control substrate 21 mounted in a resin casing 20 for controlling the hydraulic pressure control valves 5 and 6. The hydraulic pressure control valves 5 and 6, motor M and other units are electrically connected to the control substrate 21. The control substrate 21 controls these units based on signals from various sensors such as wheel speed sensors (as disclosed in JP patent publications 8-11691 and 2001-260846 (both unexamined)). Various electronic control parts 23 are mounted on the control substrate 21. A power source/control connector 24 is mounted on the outer surface of the casing 20.
Normally, the control valves 5 for pressure increase are kept open while the control valves 6 for pressure reduction are kept closed. Thus, when the brake pedal is depressed in this state, hydraulic pressure is supplied from the master cylinder into the passages 9a through the master cylinder ports 7, and then into respective wheel cylinders through the control valves 5 for pressure increase and the wheel cylinder ports 8. The brakes are thus applied to the respective wheels.
If such a vehicle control device is mounted in a vehicle brake hydraulic pressure control system such as ABS, TRC or ESC, the control substrate 21 controls the hydraulic control valves 5 and 6 based on signals from various vehicle behavioral sensors, which are mounted on the control substrate 21, thereby controlling the respective wheel cylinder pressures during e.g. electronic stability control.
With increasing demands for more luxurious and safer motor vehicles, an increasing number of today's automobiles are equipped with driving dynamics sensors, which are a type of vehicle behavioral sensors, to detect the movement of the vehicle in every direction, thereby optimally controlling the brake hydraulic pressure based on the signals from these sensors so that the vehicle can travel more smoothly and safely.
Such driving dynamics sensors are ordinarily mounted at the center of gravity of the vehicle. However, the center of gravity of the vehicle is typically not located in the engine room, in which the vehicle control device is mounted. Thus, it is usually necessary to connect them together through a wire harness.
The use of a wire harness and connectors pushes up the cost of the device, and necessitates measures for fixing it to the vehicle body, which further pushes up the cost of the device. Also, a dedicated sensor bracket is necessary for fixing to the vehicle body. To solve this problem, JP patent publication 2004-506572 proposes to mount the driving dynamics sensors in the electronic control unit 2 of the vehicle control device.
In particular, this publication proposes to mount vehicle behavioral sensors such as driving dynamics sensors S in a bulge 20a (shown by chain line in FIG. 6) formed on the rear surface of the casing 20 of the electronic control unit 2.
The bulge 20a increases the dimension of the vehicle control device in the horizontal direction of FIG. 6. This is not desirable especially in view of the fact that it is acutely desired today that vehicle parts, including the vehicle control device, be as small as possible.
An object of the present invention is to provide a compact vehicle control device carrying vehicle behavioral sensors such as driving dynamics sensors in the electronic control unit.